1. Technical Field
The present invention relates to a semiconductor light emitting element.
2. Related Art
In recent years, significant advances have been seen in the area of semiconductor light emitting elements. In particular, semiconductor light emitting elements (light emitting diodes) using semiconductor materials of GaInN, AlGaInP and GaAlAs with high light emission efficiency become commercially practical. Moreover, a group III nitride semiconductor such as gallium nitride (GaN) receives attention.
In a semiconductor light emitting element using such a group III nitride semiconductor, a laminated semiconductor layer having a light emitting diode (LED) structure configured with an n-type semiconductor layer, a light emitting layer and a p-type semiconductor layer is formed on a substrate and an electrode having optical permeability (a translucent electrode) is formed on the p-type semiconductor layer at an uppermost portion to extract emitted light through the translucent electrode.
In Japanese Patent Application Laid-Open Publication No. 2005-123501, there is described a GaN-based semiconductor light emitting element including an n-type GaN-based semiconductor layer and a p-type GaN-based semiconductor layer, in which the p-type GaN-based semiconductor layer is provided with a translucent electrode formed thereon having plural through holes for light emission, to thereby reduce light absorbance of the translucent electrode and improve emission efficiency.
Incidentally, for improving light extraction efficiency of a semiconductor light emitting element, it is required to apply uniform voltage to an entire light emitting layer to pass uniform current through the entire light emitting layer. This suppresses unevenness in light emission on a light emitting surface of the semiconductor light emitting element and improves the light extraction efficiency.
However, due to a potential gradient generated in response to current diffusion in a surface direction of the translucent electrode, the voltage applied to the light emitting layer varies depending on a position in the light emitting surface of the light emitting layer.
It is an object of the present invention to provide a semiconductor light emitting element that suppresses non-uniformity in light emission on a light emitting surface thereof.